One well-known pathology of a heart valve, primarily affecting elderly patients, is the distention of the valve annulus, this distention leading to a poor coaptation of the valves and thus a loss of sealing and effectiveness of the valve.
It is known to treat this pathology by annuloplasty, i.e., by placing a total or partial prosthetic annulus aiming to recalibrate the native valve annulus. This technique has certain drawbacks, in particular not being very suitable for elderly patients.
It is also known to implant, above the native valve, a prosthesis comprising an expandable tubular frame and a prosthetic valve mounted on this frame. The tubular frame, frequently called “stent”, has a mesh structure, and comprises an atrial portion, i.e., intended to be placed at the atrium of a heart, a ventricular portion, i.e., intended to be placed at the ventricle of a heart, and an annular portion, i.e., intended to be placed at the native valve annulus, situated between these atrial and ventricular portions. The frame may be self-expandable (in particular being made from a shape memory material) or made from an expandable material using a balloon. The prosthetic valve may in turn be made from a synthetic or natural material.
Such a prosthesis is deformable so as to be able to be placed in a catheter and is intended to be deployed from this catheter at the native valve to be treated. It may be placed using the apical approach (i.e., from the lower tip of the heart) or using a transseptal (mitral valve) or jugular or femoral (tricuspid valve) approach.
The existing prostheses of this type are not fully satisfactory, in particular having risks of migration and therefore obstruction of the ventricular ejection path, having a placement that is not always very easy to perform, not having a shape perfectly suited to that of the implantation site, and involving arranging an access orifice to the implantation site with a relatively large diameter, and which is therefore relatively traumatic.
The present invention primarily aims to resolve these essential drawbacks. It in particular aims to provide a prosthesis able to be inserted into a heart through an orifice having a diameter of about 18 mm, versus 22 mm with the existing prostheses.